Chris@102: // Boost.Geometry (aka GGL, Generic Geometry Library)
Chris@102: 
Chris@102: // Copyright (c) 2014-2015, Oracle and/or its affiliates.
Chris@102: 
Chris@102: // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
Chris@102: 
Chris@102: // Licensed under the Boost Software License version 1.0.
Chris@102: // http://www.boost.org/users/license.html
Chris@102: 
Chris@102: #ifndef BOOST_GEOMETRY_STRATEGIES_COMPARABLE_DISTANCE_RESULT_HPP
Chris@102: #define BOOST_GEOMETRY_STRATEGIES_COMPARABLE_DISTANCE_RESULT_HPP
Chris@102: 
Chris@102: #include <boost/mpl/always.hpp>
Chris@102: #include <boost/mpl/bool.hpp>
Chris@102: #include <boost/mpl/vector.hpp>
Chris@102: 
Chris@102: #include <boost/variant/variant_fwd.hpp>
Chris@102: 
Chris@102: #include <boost/geometry/core/point_type.hpp>
Chris@102: 
Chris@102: #include <boost/geometry/strategies/default_strategy.hpp>
Chris@102: #include <boost/geometry/strategies/distance.hpp>
Chris@102: 
Chris@102: #include <boost/geometry/util/compress_variant.hpp>
Chris@102: #include <boost/geometry/util/transform_variant.hpp>
Chris@102: #include <boost/geometry/util/combine_if.hpp>
Chris@102: 
Chris@102: #include <boost/geometry/algorithms/detail/distance/default_strategies.hpp>
Chris@102: 
Chris@102: 
Chris@102: namespace boost { namespace geometry
Chris@102: {
Chris@102: 
Chris@102: namespace resolve_strategy
Chris@102: {
Chris@102: 
Chris@102: template <typename Geometry1, typename Geometry2, typename Strategy>
Chris@102: struct comparable_distance_result
Chris@102:     : strategy::distance::services::return_type
Chris@102:         <
Chris@102:             typename strategy::distance::services::comparable_type
Chris@102:                 <
Chris@102:                     Strategy
Chris@102:                 >::type,
Chris@102:             typename point_type<Geometry1>::type,
Chris@102:             typename point_type<Geometry2>::type
Chris@102:         >
Chris@102: {};
Chris@102: 
Chris@102: template <typename Geometry1, typename Geometry2>
Chris@102: struct comparable_distance_result<Geometry1, Geometry2, default_strategy>
Chris@102:     : comparable_distance_result
Chris@102:         <
Chris@102:             Geometry1,
Chris@102:             Geometry2,
Chris@102:             typename detail::distance::default_strategy
Chris@102:                 <
Chris@102:                     Geometry1, Geometry2
Chris@102:                 >::type
Chris@102:         >
Chris@102: {};
Chris@102: 
Chris@102: } // namespace resolve_strategy
Chris@102: 
Chris@102: 
Chris@102: namespace resolve_variant
Chris@102: {
Chris@102: 
Chris@102: template <typename Geometry1, typename Geometry2, typename Strategy>
Chris@102: struct comparable_distance_result
Chris@102:     : resolve_strategy::comparable_distance_result
Chris@102:         <
Chris@102:             Geometry1,
Chris@102:             Geometry2,
Chris@102:             Strategy
Chris@102:         >
Chris@102: {};
Chris@102: 
Chris@102: 
Chris@102: template
Chris@102: <
Chris@102:     typename Geometry1,
Chris@102:     BOOST_VARIANT_ENUM_PARAMS(typename T),
Chris@102:     typename Strategy
Chris@102: >
Chris@102: struct comparable_distance_result
Chris@102:     <
Chris@102:         Geometry1, boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Strategy
Chris@102:     >
Chris@102: {
Chris@102:     // A set of all variant type combinations that are compatible and
Chris@102:     // implemented
Chris@102:     typedef typename util::combine_if<
Chris@102:         typename boost::mpl::vector1<Geometry1>,
Chris@102:         typename boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>::types,
Chris@102:         boost::mpl::always<boost::mpl::true_>
Chris@102:     >::type possible_input_types;
Chris@102: 
Chris@102:     // The (possibly variant) result type resulting from these combinations
Chris@102:     typedef typename compress_variant<
Chris@102:         typename transform_variant<
Chris@102:             possible_input_types,
Chris@102:             resolve_strategy::comparable_distance_result<
Chris@102:                 boost::mpl::first<boost::mpl::_>,
Chris@102:                 boost::mpl::second<boost::mpl::_>,
Chris@102:                 Strategy
Chris@102:             >,
Chris@102:             boost::mpl::back_inserter<boost::mpl::vector0<> >
Chris@102:         >::type
Chris@102:     >::type type;
Chris@102: };
Chris@102: 
Chris@102: 
Chris@102: // Distance arguments are commutative
Chris@102: template
Chris@102: <
Chris@102:     BOOST_VARIANT_ENUM_PARAMS(typename T),
Chris@102:     typename Geometry2,
Chris@102:     typename Strategy
Chris@102: >
Chris@102: struct comparable_distance_result
Chris@102:     <
Chris@102:         boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>,
Chris@102:         Geometry2,
Chris@102:         Strategy
Chris@102:     > : public comparable_distance_result
Chris@102:         <
Chris@102:             Geometry2, boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Strategy
Chris@102:         >
Chris@102: {};
Chris@102: 
Chris@102: 
Chris@102: template <BOOST_VARIANT_ENUM_PARAMS(typename T), typename Strategy>
Chris@102: struct comparable_distance_result
Chris@102:     <
Chris@102:         boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>,
Chris@102:         boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>,
Chris@102:         Strategy
Chris@102:     >
Chris@102: {
Chris@102:     // A set of all variant type combinations that are compatible and
Chris@102:     // implemented
Chris@102:     typedef typename util::combine_if
Chris@102:         <
Chris@102:             typename boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>::types,
Chris@102:             typename boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>::types,
Chris@102:             boost::mpl::always<boost::mpl::true_>
Chris@102:         >::type possible_input_types;
Chris@102: 
Chris@102:     // The (possibly variant) result type resulting from these combinations
Chris@102:     typedef typename compress_variant<
Chris@102:         typename transform_variant<
Chris@102:             possible_input_types,
Chris@102:             resolve_strategy::comparable_distance_result<
Chris@102:                 boost::mpl::first<boost::mpl::_>,
Chris@102:                 boost::mpl::second<boost::mpl::_>,
Chris@102:                 Strategy
Chris@102:             >,
Chris@102:             boost::mpl::back_inserter<boost::mpl::vector0<> >
Chris@102:         >::type
Chris@102:     >::type type;
Chris@102: };
Chris@102: 
Chris@102: } // namespace resolve_variant
Chris@102: 
Chris@102: 
Chris@102: 
Chris@102: 
Chris@102: 
Chris@102: /*!
Chris@102: \brief Meta-function defining return type of comparable_distance function
Chris@102: \ingroup distance
Chris@102: */
Chris@102: template
Chris@102: <
Chris@102:     typename Geometry1,
Chris@102:     typename Geometry2 = Geometry1,
Chris@102:     typename Strategy = void
Chris@102: >
Chris@102: struct comparable_distance_result
Chris@102:     : resolve_variant::comparable_distance_result
Chris@102:         <
Chris@102:             Geometry1, Geometry2, Strategy
Chris@102:         >
Chris@102: {};
Chris@102: 
Chris@102: template <typename Geometry1, typename Geometry2>
Chris@102: struct comparable_distance_result<Geometry1, Geometry2, void>
Chris@102:     : comparable_distance_result<Geometry1, Geometry2, default_strategy>
Chris@102: {};
Chris@102: 
Chris@102: 
Chris@102: }} // namespace boost::geometry
Chris@102: 
Chris@102: 
Chris@102: #endif // BOOST_GEOMETRY_STRATEGIES_COMPARABLE_DISTANCE_RESULT_HPP